The purpose of this investigation is to identify attributes of both workers and jobs that are etiological factors of occupational wrist injuries. The hand injury of specific concern, carpal tunnel syndrome, was selected because alarmingly high incidences have been reported in women workers who perform manual work. Two local factories, which employ a large number of women and produce automobile interiors, have agreed to cooperate in the study. This investigation is based on the thesis that exertions of the hand cause forces to be transmitted through the anatomical components of the hand, wrist, and forearm and that these forces cause inflamation of certain soft tissues--particularly the flexor synovium and the medial nerve. A two phase study is in progress to evaluate the proposed thesis. The goal of the first phase is to develop a biomechanical hand model that can be used to describe the forces in different positions of different hands. The second phase is a field study in which the frequencies of hand positions, forces and intrawrist forces that occur in a group of workers with diagnosed carpal tunnel syndrome are compared with those in a group of similar people who perform the same jobs but who do not have any diagnosed wrist or hand ailments. Also, the frequencies of hand position and forces in workers who perform jobs that are associated with a high incidence rate of carpal tunnel syndrome are compared with a group of workers who perform a similar group of jobs which are not associated with carpal tunnel syndrome.